Sudden Death Syndrome (SDS) and Soybean Cyst Nematode (SCN) are two below-ground issues that are often overlooked, resulting in a total economic loss of $1.6 billion per year.* SDS and SCN were first documented more than 40 years ago and have since spread to almost every soybean-growing state.
Once in the field, SDS and SCN cannot be eliminated, which makes it essential to protect against these yield-robbing pests.
SDS and SCN are often found in the same field
According to Jason Bond, Southern Illinois University plant pathologist, “You almost have to assume that if you have one or the other, you probably have both.” While the exact reason for the correlation is unknown, researchers recommend making management decisions based on both. When both issues are present, the two have a combined impact. SCN attacks the vascular tissue, blocking nutrient uptake and moisture. SDS attacks the plant in two phases – below ground at the root and above ground within the leaves – resulting in rapid defoliation. Mike McCarville, Bayer Tech Service representative, says SDS and SCN together contribute to the highest yield loss. “Typically, we’ll see somewhere in the two to six bushel range from nematodes,” he says. “From SDS, we’re looking at two to ten bushels of yield loss. That number only increases as the disease advances. To most effectively combat yield loss, you’ve got to find solutions that address both of these pests.”
Symptoms can be hard to spot
“For soybean growers, the one advantage of SDS is that it causes foliar symptoms, allowing growers to see there’s a problem,” says Bond. Foliar symptoms of SDS include interveinal necrosis and chlorosis (brown or yellow spots on leaves) and sudden leaf drop with petiole retention.
SCN, on the other hand, often does not present any visible symptoms, and farmers may not realize it’s in their fields. Soil testing and observation of female nematodes and cysts on the roots are the most accurate ways to diagnose an SCN infestation in the field. By the time nematode infestations become severe, soybean plants appear generally stunted with yellowing leaves.
Sudden Death Syndrome (SDS) on the left and Soybean Cyst Nematode (SCN) on the right
The seed treatment solution
Although there’s no way to completely eradicate SDS and SCN from a field, there are ways to manage the issues and prevent substantial yield loss. Seed treatments offer early-season protection from disease and insect pressures, allowing for development of stronger root systems, healthier stands and higher yields. Combining select resistant seed varieties with a seed treatment is critical, as resistant varieties are becoming less effective at warding off the pressures on their own.
McCarville recommends ILeVO®, a seed treatment from Bayer, to those growers seeking protection from both SDS and SCN. “ILeVO is really one of the greatest seed treatment innovations that we’ve seen,” says McCarville. “It gives us a way to manage, not only our adapting soybean cyst nematode populations that are really starting to challenge us in the Midwest, but also both the above- and below-ground phases of SDS.”
Because ILeVO protects seeds from the moment they’re planted, seeds can be planted earlier in the season with less risk of SDS and SCN damage – allowing growers to optimize yields and increase profitability. On average, growers are seeing a two to ten bushel-per-acre yield advantage when adding ILeVO to their current seed treatment package.**
**Depending on nematode pressure and SDS incidence or severity.
ILeVO from Bayer is the first seed treatment proven to protect against SDS and nematodes, including SCN, in the seed zone during the critical early-season growing period.
To learn more about ILeVO for management of SDS and SCN, contact your local Bayer sales representative.
*Based on USDA 2016–2017 marketing year projection for average soybean price of $9.10 per bushel. http://cornandsoybeandigest.com/blog/usda-crop-predictions-sends-corn-and-soybean-prices-lower-july-estimates.